Get the maximum age of the the cookie in seconds. Cookies older than
the maximum age are discarded. A cookie can be unset by sending a new
cookie with maximum age of 0 since it will overwrite any existing cookie
and then be immediately discarded. The default value of -1 indicates that the cookie
will be discarded at the end of the browser/application session.

Obtain a new instance of a Cookie with the same name, value, path,
domain and version as this NewCookie. This method can be used to
obtain an object that can be compared for equality with another Cookie;
since a Cookie will never compare equal to a NewCookie.